What is the differential diagnosis for sudden onset of cloudy vision in one eye following coughing?

Differential Diagnosis for Sudden Cloudy Vision After Coughing

The most critical concern is a Valsalva-induced retinal or vitreous hemorrhage, which requires urgent ophthalmologic evaluation within 24 hours to prevent permanent vision loss.

Immediate Life- and Vision-Threatening Conditions

Valsalva Retinopathy (Most Likely)

• Sudden increase in intrathoracic and intraocular venous pressure from forceful coughing can rupture retinal capillaries, causing preretinal or subhyaloid hemorrhage that presents as acute cloudy or blurred vision 1
• This typically occurs unilaterally and presents immediately following the Valsalva maneuver (coughing, straining, vomiting) 1
• The hemorrhage settles in front of the retina, creating a characteristic "cloudy" appearance to vision 2
• Urgent ophthalmologic referral within 24 hours is mandatory to assess extent of hemorrhage and rule out retinal tear 3, 1

Retinal Detachment or Tear

• Sudden onset of visual changes including clouding, floaters, or visual field defects requires emergency ophthalmologic assessment 2, 1
• Forceful coughing can generate sufficient vitreoretinal traction to cause retinal tears, particularly in patients with high myopia or previous eye surgery 4
• Even without flashes of light, acute visual changes warrant urgent evaluation as 14-23% of patients with new visual symptoms have retinal tears 4
• Delay in diagnosis can result in progression to full retinal detachment with permanent vision loss 2, 4

Vitreous Hemorrhage

• Coughing-induced rupture of vitreous vessels presents as sudden cloudy or hazy vision, often described as "looking through a veil" 1
• This represents a true ophthalmic emergency requiring same-day ophthalmologic evaluation 3, 1

Secondary Considerations

Posterior Vitreous Detachment (PVD)

• Acute onset of floaters or cloudy vision may indicate PVD, which carries significant risk for retinal tear formation 4
• The mechanical stress from coughing can precipitate PVD in predisposed individuals 4
• Risk factors include high myopia, recent cataract surgery, ocular trauma, or family history of retinal problems 4

Acute Angle-Closure Glaucoma

• While less likely to be triggered by coughing alone, this presents with sudden vision loss, cloudy/hazy vision, severe eye pain, and halos around lights 1
• This is a true emergency requiring immediate treatment to prevent permanent optic nerve damage 2, 1
• The cloudy vision results from corneal edema secondary to acutely elevated intraocular pressure 1

Subconjunctival Hemorrhage

• Common after coughing but typically does NOT cause cloudy vision—only visible blood on the white of the eye 3
• If cloudy vision is present with subconjunctival hemorrhage, suspect concurrent intraocular pathology 1

Critical Red Flags Requiring Emergency Evaluation

• Any sudden vision loss or clouding in one eye is an ophthalmic emergency until proven otherwise 3, 2, 1
• Associated symptoms requiring immediate assessment include: new floaters, flashes of light, visual field defects, severe eye pain, or halos around lights 4, 1
• Do not wait for symptoms to worsen—permanent vision loss can occur within hours for conditions like retinal artery occlusion or acute angle-closure glaucoma 3, 1

Immediate Management Algorithm

1. Refer immediately (same day) to ophthalmology or emergency department with ophthalmologic capability 3, 1
2. Instruct patient to avoid further Valsalva maneuvers (straining, heavy lifting, forceful coughing) until evaluated 1
3. Do not attempt to treat empirically—definitive diagnosis requires dilated fundoscopic examination and potentially optical coherence tomography 2, 1
4. Document visual acuity in both eyes before referral 1

Common Pitfalls to Avoid

• Never dismiss unilateral cloudy vision as "just a floater" or "eye strain"—this can result in preventable blindness 4, 1
• Do not delay referral waiting for symptoms to resolve spontaneously, as retinal tears can progress to detachment within days 2, 4
• Do not assume normal external eye examination excludes serious intraocular pathology—most vision-threatening conditions require dilated fundoscopic examination for diagnosis 2, 1
• Absence of pain does not exclude serious pathology—retinal detachment and vitreous hemorrhage are often painless 2, 1